Corrupt key?

[Paul Wolstenholme]

I have some data that was encrypted with a key that may have become 
corrupt. When I try to decrypt a file it ends with:

gpg: decryption failed: secret key not available
gpg: [don't know]: invalid packet (ctb=79)

Is there a way I can recover from this.

Here is the output from my tests:

1. encryption:
gpg -vvv -e -a -r www --homedir /www/.gnupg --always-trust 1.txt
gpg: loaded digest 2
gpg: using secondary key CD4BB419 instead of primary key CB0C618B
gpg: key 5CEDA6C1: accepted as trusted key.
gpg: No trust check due to --always-trust option
gpg: reading from `1.txt'
File `1.txt.asc' exists. Overwrite (y/N)? y
gpg: writing to `1.txt.asc'
gpg: ELG-E/RIJNDAEL encrypted for: CD4BB419 Fatman (Fatman key) 
<www at fatman.com>

2. decrypt
www-data at sonicyouth:~$ gpg -v -d  --homedir /www/.gnupg 1.txt.asc
gpg: armor header: Version: GnuPG v1.0.6 (GNU/Linux)
gpg: armor header: Comment: For info see http://www.gnupg.org
gpg: public key is CD4BB419
gpg: using secondary key CD4BB419 instead of primary key CB0C618B
gpg: encrypted with 1024-bit ELG-E key, ID CD4BB419, created 2003-10-17
       "Fatman (Fatman key) <www at fatman.com>"
gpg: decryption failed: secret key not available
gpg: packet(3) with unknown version 70